Inflammatory chemokines CCL3 (MIP-1?) and CCL4 (MIP-1?) are important in orchestrating nonrandom naive CD8+ T cell contacts with dendritic cells in vaccinated lymph nodes (LNs) and can enhance memory T cell generation. We hypothesize that incorporating CCL3 and CCL4 into tumor microenvironment can enhance anti-tumor immunity. Using the murine colon tumor model CT26, we generated tumors that secret CCL3 or CCL4 and inoculate them live into the footpad of nave immunocompetent recipients. Tumor growth kinetic measurements showed that CCL3-secreting tumors resulted in either a CD8+ T cell dependent slowing of tumor progression or complete regression in immunocompetent mice and protected subsequent lethal tumor challenge when used as a vaccine. Next, using fluorescence-activated cell sorting analysis (FACS) we analyzed the effects of lymphocyte recruitment to the LN draining the metastatic tumor by fluorescence- activated cell sorting analysis 3 and 5 days post-tumor injection. Mice inoculated with CCL3-secreting tumors resulted in similar increases in CD4+ and CD8+ T cells ranging from 1.3 to 1.7-fold increase from WT tumors and 1.3-fold increase from CCL4-secreting tumors on day 3. By day 5 the T cell accumulation in CCL3- secreting tumors reached similar levels as that of WT and CCL4-secreting tumors. Furthermore, dynamic intravital 2-photon microscopy and tissue histology studies further revealed that tumors occupy the B-cell follicle during early metastasis, and exogenous CCL3 and CCL4 gradient may potentially alter lymphocyte homeostasis in tumor draining LNs, resulting in immune activation rather than tolerance against CT26. We propose to interrogate biological effect of CCL3 on immune cell recruitment, activation, retention and effector functional delivery in the draining LNs following CCL3- or CCL4-secreting CT26 tumor inoculation. These studies include functional activation, migration and chemokine receptor expression of dendritic cells and lymphocytes upon exposure to CCL3. Furthermore, we propose to study the dynamic cell-cell interaction between CCL3-secreting, CCL4-secreting, or wild type CT26 tumor cells and various immune cells in the tumor-infiltrating LN within the first 5 days following tumor inoculation. These studies will provide scientific rationale for the exploration of incorporating inflammatory chemokines such as CCL3 as a therapeutic adjuvant to anti-tumor immunotherapy.